diff --git a/tests/e2e/golden/osism_e2e-breakout-derived_config_db.json b/tests/e2e/golden/osism_e2e-breakout-derived_config_db.json
new file mode 100644
index 00000000..94dbe170
--- /dev/null
+++ b/tests/e2e/golden/osism_e2e-breakout-derived_config_db.json
@@ -0,0 +1,647 @@
+{
+  "BGP_GLOBALS": {
+    "default": {
+      "always_compare_med": "true",
+      "ebgp_requires_policy": "false",
+      "external_compare_router_id": "false",
+      "fast_external_failover": "true",
+      "holdtime": "180",
+      "ignore_as_path_length": "false",
+      "keepalive": "60",
+      "load_balance_mp_relax": "false",
+      "log_nbr_state_changes": "true",
+      "network_import_check": "true"
+    }
+  },
+  "BGP_GLOBALS_AF": {
+    "default|ipv4_unicast": {
+      "ibgp_equal_cluster_length": "false",
+      "max_ebgp_paths": "2",
+      "max_ibgp_paths": "2",
+      "route_flap_dampen": "false"
+    },
+    "default|ipv6_unicast": {
+      "ibgp_equal_cluster_length": "false",
+      "max_ebgp_paths": "2",
+      "max_ibgp_paths": "2"
+    },
+    "default|l2vpn_evpn": {
+      "advertise-all-vni": "true",
+      "advertise-svi-ip": "true",
+      "dad-enabled": "true"
+    }
+  },
+  "BGP_GLOBALS_AF_NETWORK": {},
+  "BGP_GLOBALS_ROUTE_ADVERTISE": {
+    "default|L2VPN_EVPN|IPV4_UNICAST": {},
+    "default|L2VPN_EVPN|IPV6_UNICAST": {}
+  },
+  "BGP_NEIGHBOR": {},
+  "BGP_NEIGHBOR_AF": {},
+  "BREAKOUT_CFG": {
+    "Ethernet0": {
+      "breakout_owner": "MANUAL",
+      "brkout_mode": "4x100G",
+      "port": "1/1"
+    }
+  },
+  "BREAKOUT_PORTS": {
+    "Ethernet0": {
+      "master": "Ethernet0"
+    },
+    "Ethernet2": {
+      "master": "Ethernet0"
+    },
+    "Ethernet4": {
+      "master": "Ethernet0"
+    },
+    "Ethernet6": {
+      "master": "Ethernet0"
+    }
+  },
+  "DEVICE_METADATA": {
+    "localhost": {
+      "hostname": "e2e-breakout-derived",
+      "hwsku": "Accton-AS9726-32D",
+      "mac": "00:00:00:00:00:00",
+      "platform": "x86_64-accton_as9726_32d-r0"
+    }
+  },
+  "DNS_NAMESERVER": {},
+  "INTERFACE": {},
+  "LOOPBACK": {},
+  "LOOPBACK_INTERFACE": {},
+  "MGMT_INTERFACE": {},
+  "NTP_SERVER": {},
+  "PORT": {
+    "Ethernet0": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/1",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "73,74",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet104": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/14",
+      "autoneg": "off",
+      "index": "14",
+      "lanes": "137,138,139,140,141,142,143,144",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet112": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/15",
+      "autoneg": "off",
+      "index": "15",
+      "lanes": "145,146,147,148,149,150,151,152",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet120": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/16",
+      "autoneg": "off",
+      "index": "16",
+      "lanes": "153,154,155,156,157,158,159,160",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet128": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/17",
+      "autoneg": "off",
+      "index": "17",
+      "lanes": "169,170,171,172,173,174,175,176",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet136": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/18",
+      "autoneg": "off",
+      "index": "18",
+      "lanes": "161,162,163,164,165,166,167,168",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet144": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/19",
+      "autoneg": "off",
+      "index": "19",
+      "lanes": "177,178,179,180,181,182,183,184",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet152": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/20",
+      "autoneg": "off",
+      "index": "20",
+      "lanes": "185,186,187,188,189,190,191,192",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet16": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/3",
+      "autoneg": "off",
+      "index": "3",
+      "lanes": "81,82,83,84,85,86,87,88",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet160": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/21",
+      "autoneg": "off",
+      "index": "21",
+      "lanes": "1,2,3,4,5,6,7,8",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet168": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/22",
+      "autoneg": "off",
+      "index": "22",
+      "lanes": "9,10,11,12,13,14,15,16",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet176": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/23",
+      "autoneg": "off",
+      "index": "23",
+      "lanes": "17,18,19,20,21,22,23,24",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet184": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/24",
+      "autoneg": "off",
+      "index": "24",
+      "lanes": "25,26,27,28,29,30,31,32",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet192": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/25",
+      "autoneg": "off",
+      "index": "25",
+      "lanes": "201,202,203,204,205,206,207,208",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet2": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/3",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "75,76",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet200": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/26",
+      "autoneg": "off",
+      "index": "26",
+      "lanes": "193,194,195,196,197,198,199,200",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet208": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/27",
+      "autoneg": "off",
+      "index": "27",
+      "lanes": "217,218,219,220,221,222,223,224",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet216": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/28",
+      "autoneg": "off",
+      "index": "28",
+      "lanes": "209,210,211,212,213,214,215,216",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet224": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/29",
+      "autoneg": "off",
+      "index": "29",
+      "lanes": "233,234,235,236,237,238,239,240",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet232": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/30",
+      "autoneg": "off",
+      "index": "30",
+      "lanes": "225,226,227,228,229,230,231,232",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet24": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/4",
+      "autoneg": "off",
+      "index": "4",
+      "lanes": "89,90,91,92,93,94,95,96",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet240": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/31",
+      "autoneg": "off",
+      "index": "31",
+      "lanes": "249,250,251,252,253,254,255,256",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet248": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/32",
+      "autoneg": "off",
+      "index": "32",
+      "lanes": "241,242,243,244,245,246,247,248",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet256": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/33",
+      "autoneg": "off",
+      "index": "33",
+      "lanes": "259",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "10000",
+      "unreliable_los": "auto",
+      "valid_speeds": "10000"
+    },
+    "Ethernet257": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/34",
+      "autoneg": "off",
+      "index": "34",
+      "lanes": "260",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "10000",
+      "unreliable_los": "auto",
+      "valid_speeds": "10000"
+    },
+    "Ethernet32": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/5",
+      "autoneg": "off",
+      "index": "5",
+      "lanes": "97,98,99,100,101,102,103,104",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "tagged_vlans": [
+        "200"
+      ],
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet4": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/5",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "77,78",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet40": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/6",
+      "autoneg": "off",
+      "index": "6",
+      "lanes": "105,106,107,108,109,110,111,112",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet48": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/7",
+      "autoneg": "off",
+      "index": "7",
+      "lanes": "113,114,115,116,117,118,119,120",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet56": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/8",
+      "autoneg": "off",
+      "index": "8",
+      "lanes": "121,122,123,124,125,126,127,128",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet6": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/7",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "79,80",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet64": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/9",
+      "autoneg": "off",
+      "index": "9",
+      "lanes": "41,42,43,44,45,46,47,48",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet72": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/10",
+      "autoneg": "off",
+      "index": "10",
+      "lanes": "33,34,35,36,37,38,39,40",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet8": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/2",
+      "autoneg": "off",
+      "index": "2",
+      "lanes": "65,66,67,68,69,70,71,72",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet80": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/11",
+      "autoneg": "off",
+      "index": "11",
+      "lanes": "49,50,51,52,53,54,55,56",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet88": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/12",
+      "autoneg": "off",
+      "index": "12",
+      "lanes": "57,58,59,60,61,62,63,64",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet96": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/13",
+      "autoneg": "off",
+      "index": "13",
+      "lanes": "129,130,131,132,133,134,135,136",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    }
+  },
+  "PORTCHANNEL": {},
+  "PORTCHANNEL_INTERFACE": {},
+  "PORTCHANNEL_MEMBER": {},
+  "ROUTE_REDISTRIBUTE": {
+    "default|connected|bgp|ipv4": {},
+    "default|connected|bgp|ipv6": {}
+  },
+  "SNMP_SERVER": {
+    "SYSTEM": {
+      "sysContact": "e2e@example.com",
+      "sysLocation": "E2E Lab",
+      "traps": "enable"
+    }
+  },
+  "SNMP_SERVER_GROUP_MEMBER": {
+    "monitoring|e2e-monitor": {
+      "securityModel": [
+        "usm"
+      ]
+    }
+  },
+  "SNMP_SERVER_PARAMS": {
+    "targetEntry1": {
+      "security-level": "auth-priv",
+      "user": "e2e-monitor"
+    }
+  },
+  "SNMP_SERVER_TARGET": {
+    "targetEntry1": {
+      "ip": "172.16.10.254",
+      "port": "162",
+      "retries": "3",
+      "tag": [
+        "trapNotify",
+        "mgmt"
+      ],
+      "targetParams": "targetEntry1",
+      "timeout": "1500"
+    }
+  },
+  "SNMP_SERVER_USER": {
+    "e2e-monitor": {
+      "aesKey": "OBFUSCATEDPRIVSECRET",
+      "shaKey": "OBFUSCATEDAUTHSECRET"
+    }
+  },
+  "STATIC_ROUTE": {},
+  "SYSLOG_SERVER": {
+    "172.16.10.254": {
+      "message-type": "log",
+      "protocol": "UDP",
+      "remote-port": "514",
+      "severity": "info",
+      "vrf_name": "mgmt"
+    }
+  },
+  "VERSIONS": {
+    "DATABASE": {
+      "VERSION": "version_4_0_1"
+    }
+  },
+  "VLAN": {
+    "Vlan200": {
+      "admin_status": "up",
+      "autostate": "enable",
+      "members": [
+        "Ethernet32"
+      ],
+      "vlanid": "200"
+    }
+  },
+  "VLAN_INTERFACE": {},
+  "VLAN_MEMBER": {
+    "Vlan200|Ethernet32": {
+      "tagging_mode": "tagged"
+    }
+  },
+  "VRF": {
+    "default": {
+      "enabled": "true"
+    }
+  },
+  "VXLAN_EVPN_NVO": {},
+  "VXLAN_TUNNEL": {},
+  "VXLAN_TUNNEL_MAP": {}
+}
diff --git a/tests/e2e/golden/osism_e2e-breakout-explicit_config_db.json b/tests/e2e/golden/osism_e2e-breakout-explicit_config_db.json
new file mode 100644
index 00000000..e9b0fe30
--- /dev/null
+++ b/tests/e2e/golden/osism_e2e-breakout-explicit_config_db.json
@@ -0,0 +1,631 @@
+{
+  "BGP_GLOBALS": {
+    "default": {
+      "always_compare_med": "true",
+      "ebgp_requires_policy": "false",
+      "external_compare_router_id": "false",
+      "fast_external_failover": "true",
+      "holdtime": "180",
+      "ignore_as_path_length": "false",
+      "keepalive": "60",
+      "load_balance_mp_relax": "false",
+      "log_nbr_state_changes": "true",
+      "network_import_check": "true"
+    }
+  },
+  "BGP_GLOBALS_AF": {
+    "default|ipv4_unicast": {
+      "ibgp_equal_cluster_length": "false",
+      "max_ebgp_paths": "2",
+      "max_ibgp_paths": "2",
+      "route_flap_dampen": "false"
+    },
+    "default|ipv6_unicast": {
+      "ibgp_equal_cluster_length": "false",
+      "max_ebgp_paths": "2",
+      "max_ibgp_paths": "2"
+    },
+    "default|l2vpn_evpn": {
+      "advertise-all-vni": "true",
+      "advertise-svi-ip": "true",
+      "dad-enabled": "true"
+    }
+  },
+  "BGP_GLOBALS_AF_NETWORK": {},
+  "BGP_GLOBALS_ROUTE_ADVERTISE": {
+    "default|L2VPN_EVPN|IPV4_UNICAST": {},
+    "default|L2VPN_EVPN|IPV6_UNICAST": {}
+  },
+  "BGP_NEIGHBOR": {},
+  "BGP_NEIGHBOR_AF": {},
+  "BREAKOUT_CFG": {
+    "Ethernet0": {
+      "breakout_owner": "MANUAL",
+      "brkout_mode": "4x100G",
+      "port": "1/1"
+    }
+  },
+  "BREAKOUT_PORTS": {
+    "Ethernet0": {
+      "master": "Ethernet0"
+    },
+    "Ethernet2": {
+      "master": "Ethernet0"
+    },
+    "Ethernet4": {
+      "master": "Ethernet0"
+    },
+    "Ethernet6": {
+      "master": "Ethernet0"
+    }
+  },
+  "DEVICE_METADATA": {
+    "localhost": {
+      "hostname": "e2e-breakout-explicit",
+      "hwsku": "Accton-AS9726-32D",
+      "mac": "00:00:00:00:00:00",
+      "platform": "x86_64-accton_as9726_32d-r0"
+    }
+  },
+  "DNS_NAMESERVER": {},
+  "INTERFACE": {},
+  "LOOPBACK": {},
+  "LOOPBACK_INTERFACE": {},
+  "MGMT_INTERFACE": {},
+  "NTP_SERVER": {},
+  "PORT": {
+    "Ethernet0": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/1",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "73,74",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet104": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/14",
+      "autoneg": "off",
+      "index": "14",
+      "lanes": "137,138,139,140,141,142,143,144",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet112": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/15",
+      "autoneg": "off",
+      "index": "15",
+      "lanes": "145,146,147,148,149,150,151,152",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet120": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/16",
+      "autoneg": "off",
+      "index": "16",
+      "lanes": "153,154,155,156,157,158,159,160",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet128": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/17",
+      "autoneg": "off",
+      "index": "17",
+      "lanes": "169,170,171,172,173,174,175,176",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet136": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/18",
+      "autoneg": "off",
+      "index": "18",
+      "lanes": "161,162,163,164,165,166,167,168",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet144": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/19",
+      "autoneg": "off",
+      "index": "19",
+      "lanes": "177,178,179,180,181,182,183,184",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet152": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/20",
+      "autoneg": "off",
+      "index": "20",
+      "lanes": "185,186,187,188,189,190,191,192",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet16": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/3",
+      "autoneg": "off",
+      "index": "3",
+      "lanes": "81,82,83,84,85,86,87,88",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet160": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/21",
+      "autoneg": "off",
+      "index": "21",
+      "lanes": "1,2,3,4,5,6,7,8",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet168": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/22",
+      "autoneg": "off",
+      "index": "22",
+      "lanes": "9,10,11,12,13,14,15,16",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet176": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/23",
+      "autoneg": "off",
+      "index": "23",
+      "lanes": "17,18,19,20,21,22,23,24",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet184": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/24",
+      "autoneg": "off",
+      "index": "24",
+      "lanes": "25,26,27,28,29,30,31,32",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet192": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/25",
+      "autoneg": "off",
+      "index": "25",
+      "lanes": "201,202,203,204,205,206,207,208",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet2": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/3",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "75,76",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet200": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/26",
+      "autoneg": "off",
+      "index": "26",
+      "lanes": "193,194,195,196,197,198,199,200",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet208": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/27",
+      "autoneg": "off",
+      "index": "27",
+      "lanes": "217,218,219,220,221,222,223,224",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet216": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/28",
+      "autoneg": "off",
+      "index": "28",
+      "lanes": "209,210,211,212,213,214,215,216",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet224": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/29",
+      "autoneg": "off",
+      "index": "29",
+      "lanes": "233,234,235,236,237,238,239,240",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet232": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/30",
+      "autoneg": "off",
+      "index": "30",
+      "lanes": "225,226,227,228,229,230,231,232",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet24": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/4",
+      "autoneg": "off",
+      "index": "4",
+      "lanes": "89,90,91,92,93,94,95,96",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet240": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/31",
+      "autoneg": "off",
+      "index": "31",
+      "lanes": "249,250,251,252,253,254,255,256",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet248": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/32",
+      "autoneg": "off",
+      "index": "32",
+      "lanes": "241,242,243,244,245,246,247,248",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet256": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/33",
+      "autoneg": "off",
+      "index": "33",
+      "lanes": "259",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "10000",
+      "unreliable_los": "auto",
+      "valid_speeds": "10000"
+    },
+    "Ethernet257": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/34",
+      "autoneg": "off",
+      "index": "34",
+      "lanes": "260",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "10000",
+      "unreliable_los": "auto",
+      "valid_speeds": "10000"
+    },
+    "Ethernet32": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/5",
+      "autoneg": "off",
+      "index": "5",
+      "lanes": "97,98,99,100,101,102,103,104",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet4": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/5",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "77,78",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet40": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/6",
+      "autoneg": "off",
+      "index": "6",
+      "lanes": "105,106,107,108,109,110,111,112",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet48": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/7",
+      "autoneg": "off",
+      "index": "7",
+      "lanes": "113,114,115,116,117,118,119,120",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet56": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/8",
+      "autoneg": "off",
+      "index": "8",
+      "lanes": "121,122,123,124,125,126,127,128",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet6": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/1/7",
+      "autoneg": "off",
+      "index": "1",
+      "lanes": "79,80",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "100000",
+      "unreliable_los": "auto",
+      "valid_speeds": "100000,50000,25000,10000,1000"
+    },
+    "Ethernet64": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/9",
+      "autoneg": "off",
+      "index": "9",
+      "lanes": "41,42,43,44,45,46,47,48",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet72": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/10",
+      "autoneg": "off",
+      "index": "10",
+      "lanes": "33,34,35,36,37,38,39,40",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet8": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/2",
+      "autoneg": "off",
+      "index": "2",
+      "lanes": "65,66,67,68,69,70,71,72",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet80": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/11",
+      "autoneg": "off",
+      "index": "11",
+      "lanes": "49,50,51,52,53,54,55,56",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet88": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/12",
+      "autoneg": "off",
+      "index": "12",
+      "lanes": "57,58,59,60,61,62,63,64",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    },
+    "Ethernet96": {
+      "admin_status": "down",
+      "adv_speeds": "all",
+      "alias": "Eth1/13",
+      "autoneg": "off",
+      "index": "13",
+      "lanes": "129,130,131,132,133,134,135,136",
+      "link_training": "off",
+      "mtu": "9100",
+      "speed": "400000",
+      "unreliable_los": "auto",
+      "valid_speeds": "400000"
+    }
+  },
+  "PORTCHANNEL": {},
+  "PORTCHANNEL_INTERFACE": {},
+  "PORTCHANNEL_MEMBER": {},
+  "ROUTE_REDISTRIBUTE": {
+    "default|connected|bgp|ipv4": {},
+    "default|connected|bgp|ipv6": {}
+  },
+  "SNMP_SERVER": {
+    "SYSTEM": {
+      "sysContact": "e2e@example.com",
+      "sysLocation": "E2E Lab",
+      "traps": "enable"
+    }
+  },
+  "SNMP_SERVER_GROUP_MEMBER": {
+    "monitoring|e2e-monitor": {
+      "securityModel": [
+        "usm"
+      ]
+    }
+  },
+  "SNMP_SERVER_PARAMS": {
+    "targetEntry1": {
+      "security-level": "auth-priv",
+      "user": "e2e-monitor"
+    }
+  },
+  "SNMP_SERVER_TARGET": {
+    "targetEntry1": {
+      "ip": "172.16.10.254",
+      "port": "162",
+      "retries": "3",
+      "tag": [
+        "trapNotify",
+        "mgmt"
+      ],
+      "targetParams": "targetEntry1",
+      "timeout": "1500"
+    }
+  },
+  "SNMP_SERVER_USER": {
+    "e2e-monitor": {
+      "aesKey": "OBFUSCATEDPRIVSECRET",
+      "shaKey": "OBFUSCATEDAUTHSECRET"
+    }
+  },
+  "STATIC_ROUTE": {},
+  "SYSLOG_SERVER": {
+    "172.16.10.254": {
+      "message-type": "log",
+      "protocol": "UDP",
+      "remote-port": "514",
+      "severity": "info",
+      "vrf_name": "mgmt"
+    }
+  },
+  "VERSIONS": {
+    "DATABASE": {
+      "VERSION": "version_4_0_1"
+    }
+  },
+  "VLAN": {},
+  "VLAN_INTERFACE": {},
+  "VLAN_MEMBER": {},
+  "VRF": {
+    "default": {
+      "enabled": "true"
+    }
+  },
+  "VXLAN_EVPN_NVO": {},
+  "VXLAN_TUNNEL": {},
+  "VXLAN_TUNNEL_MAP": {}
+}
diff --git a/tests/e2e/scenario/devicetypes/Edgecore/9726-32D-E2E.yaml b/tests/e2e/scenario/devicetypes/Edgecore/9726-32D-E2E.yaml
new file mode 100644
index 00000000..c161befd
--- /dev/null
+++ b/tests/e2e/scenario/devicetypes/Edgecore/9726-32D-E2E.yaml
@@ -0,0 +1,37 @@
+---
+# Minimal device type for the SONiC E2E breakout regression scenarios.
+#
+# This is not a faithful model of the real 9726-32D; it defines only the
+# interfaces the scenarios need. Config generation is driven by the hwsku
+# custom field (Accton-AS9726-32D on the scenario devices), not by this
+# device type -- the device type only controls which NetBox interfaces
+# exist.
+#
+# The interface layout mirrors how real deployments model breakouts (the
+# NetBox EthX/Y/Z sub-port notation, speed derived from the interface
+# type rather than set explicitly). On the 8-lane 400G master Ethernet0
+# (Accton-AS9726-32D.ini), the four sub-ports Eth1/1/1..4 map to
+# Ethernet0/2/4/6 as a 4x100G breakout; the three non-master sub-ports are
+# absent from the .ini and so are generated by _add_missing_breakout_ports,
+# where the sub-port speed is read back from the collected NetBox data.
+#
+# Eth1/5 is a plain (non-breakout) 100G port used for VLAN coverage.
+manufacturer: Edgecore
+model: 9726-32D-E2E
+slug: edgecore-9726-32d-e2e
+u_height: 1.0
+is_full_depth: true
+interfaces:
+  - name: eth0
+    type: 1000base-t
+    mgmt_only: true
+  - name: Eth1/1/1
+    type: 100gbase-x-qsfp28
+  - name: Eth1/1/2
+    type: 100gbase-x-qsfp28
+  - name: Eth1/1/3
+    type: 100gbase-x-qsfp28
+  - name: Eth1/1/4
+    type: 100gbase-x-qsfp28
+  - name: Eth1/5
+    type: 100gbase-x-qsfp28
diff --git a/tests/e2e/scenario/resources/500-breakout.yml b/tests/e2e/scenario/resources/500-breakout.yml
new file mode 100644
index 00000000..d41ac0ae
--- /dev/null
+++ b/tests/e2e/scenario/resources/500-breakout.yml
@@ -0,0 +1,98 @@
+---
+# Scenario overlay for the SONiC E2E golden test.
+#
+# The bundled netbox-manager example models no breakout ports and sets no
+# explicit interface speeds, so the breakout code paths and the kbps->Mbps
+# speed handling are never exercised by it. These devices add that
+# coverage. They reuse the site / location / tenant / roles / tags / custom
+# fields created by 100-base.yml, and take the next free positions in the
+# shared E2E rack so they never collide with the base devices.
+#
+# Both devices use the edgecore-9726-32d-e2e device type (hwsku
+# Accton-AS9726-32D) and break Eth1/1 into a 4x100G group. They differ
+# only in how the sub-port speed reaches NetBox:
+#
+#   e2e-breakout-derived   speed derived from the interface type
+#                          (100gbase-x-qsfp28 -> 100000 Mbps); no explicit
+#                          speed. This is how real deployments model
+#                          breakouts.
+#   e2e-breakout-explicit  the same sub-ports with an explicit NetBox speed
+#                          set in kbps (100000000), the other unit the
+#                          collection step must normalise.
+#
+# Both must yield sub-port speed 100000 in the generated config.
+
+# --- Derived-speed breakout (the real-deployment shape) --------------------
+
+- device:
+    name: e2e-breakout-derived
+    tenant: Testbed
+    site: Discworld
+    location: Ankh-Morpork
+    rack: E2E
+    device_type: edgecore-9726-32d-e2e
+    device_role: leaf
+    face: front
+    position: 6
+    status: active
+    tags:
+      - managed-by-metalbox
+    custom_fields:
+      sonic_parameters:
+        hwsku: Accton-AS9726-32D
+        version: 4.5.0
+
+# Tagged VLAN on the plain (non-breakout) port, exercising the VLAN and
+# tagged-VLAN-to-port paths.
+- device_interface:
+    device: e2e-breakout-derived
+    name: Eth1/5
+    type: 100gbase-x-qsfp28
+    mode: tagged
+    tagged_vlans:
+      - name: data
+        site: Discworld
+
+# --- Explicit-speed breakout (the other speed unit) -----------------------
+
+- device:
+    name: e2e-breakout-explicit
+    tenant: Testbed
+    site: Discworld
+    location: Ankh-Morpork
+    rack: E2E
+    device_type: edgecore-9726-32d-e2e
+    device_role: leaf
+    face: front
+    position: 7
+    status: active
+    tags:
+      - managed-by-metalbox
+    custom_fields:
+      sonic_parameters:
+        hwsku: Accton-AS9726-32D
+        version: 4.5.0
+
+- device_interface:
+    device: e2e-breakout-explicit
+    name: Eth1/1/1
+    type: 100gbase-x-qsfp28
+    speed: 100000000
+
+- device_interface:
+    device: e2e-breakout-explicit
+    name: Eth1/1/2
+    type: 100gbase-x-qsfp28
+    speed: 100000000
+
+- device_interface:
+    device: e2e-breakout-explicit
+    name: Eth1/1/3
+    type: 100gbase-x-qsfp28
+    speed: 100000000
+
+- device_interface:
+    device: e2e-breakout-explicit
+    name: Eth1/1/4
+    type: 100gbase-x-qsfp28
+    speed: 100000000